Prep *is* everything in a good paint job... take the time to prep well, and you can hit it with rattle cans and get a decent looking finish that will last for years. Don't prep well, and even the best quality paint will fail quickly.
Once you decide how thorough a job you're going to do (take it completely apart vs. minimal disassembly), you'll start by removing paint, dirt, grease, etc. Note that if your current paint is not chalky, flaking or rusted, you could possibly get away with lightly sanding and painting right over what you have.
However, most 60-year-old tractors won't fall into that category. Mine surely didn't.
I used a combination of strippers (from oven cleaner to aircraft stripper) on the large cast parts, and made a CHEAP
electrolysis tank to remove paint from the smaller parts.
Some parts had four and five layers of paint on them (including latex house paint). Once done with strippers or the e-tank, everything got spritzed with phosphoric acid (available at your local big-box lumber store as concrete etcher) to stop the flash oxidation (surface rust) that starts immediately once the metal is exposed - it's not a long-term solution, but will hold you for a few weeks if you're not too humid.
I then came back with an angle-grinder and a cupped wire-wheel to clean away any remaining cruft. Then used lacquer thinner to wipe any remaining grease from the surface and once dry, used a 3" brush to apply red oxide primer, or rattle can primer for some of the smaller parts.
BTW - make sure you are using the same type of primer as top coat - enamel and lacquer don't mix well... Also use proper personal protective equipment (safety glasses and gloves while wire brushing, good ventilation for the e-tank since it generates hydrogen gas, etc.).
I built the tractor back up as I completed the painting and other refurbishing work...
Once all the "red" parts were together, I lightly sanded the primer to scuff it up a bit so the topcoat would stick better.
I then mixed up Rustoleum Sunrise Red with Valspar hardener (per instructions on the cans) and shot two coats with my ancient spray gun. I have an equally ancient 30 gallon compressor (don't know the HP, but it's not that much). If you've never used a spray gun on a compressor before and that's the route you go, find something else to practice a bit on first. Too much air and you get a lot of dry overspray and early paint failure. Too little, and you get a sputtery, runny mess. Google around and you'll find info on proper technique.
Did basically the same process for the "grey" parts (two coats), but with a bit more sanding out of the primer before topcoat:
I used rattle cans for the trim colors (black, gunmetal grey on the exhaust):
Finished putting it together, and went for my first drive!
Hope that's of help. More pics are
here.
Note that there are certainly other paths to get to a nice finish - this is the one I took, largely driven by available tools, experience and skill level...
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